I learned the different methods to provision external users in Salesforce.

* You can create Customers and Partners

* depending on account type you can create certain users
* personaccount and contact – customers
* account – partner/customer
* Account owner must have a role
* You can manually create contact and enable as customer or partner
* Partners have roles when enabled
* You can self register

* assign the profile in setup or
* assign in the selfregister code this overrides the setup
* assign the role
* assign the account
* You can sign up via API using the following methods

* createPortalUser
* createPersonAccountPortalUser
* Social sign on to provision a user –
* You can Just in time provision using SAML

* combine saml with more attributes and SSO to provision a user
* SAML Subject NameId as the Federation ID
* does not work for PersonAccount
* Contact email must be unique accross all even none external users
* account name and number must be unique or causes duplicate error
* Data loader
* Bulk Provisioning via API

* use same api methods – can you pass bulk here? api limits apply
* Identity Connect with Active Directory

https://developer.salesforce.com/blogs/developer-relations/2014/06/how-to-provision-salesforce-communities-users.html